1. Technological Field
The present disclosure relates to a method and system for measuring a capacitance difference between capacitive elements.
2. Description of the Related Technology
Measuring capacitance is used in many test structures to assess technology performance. However the scaling of technology has resulted in a reduction of capacitance values that are of practical use in circuits. Current methods to assess the matching of capacitance are not adequate to measure accurately the difference of very small capacitances (100 fF and well below) that are relevant for circuit design.
For example, a charge based capacitance measurement method is known from Dennis Sylvester et al., “Investigation of Interconnect Capacitance Characterization Using Charge-Based Capacitance Measurement (CBCM) Technique and Three-Dimensional Simulation,” IEEE JSSC 1998. This method is capable of measuring absolute capacitance of a capacitor, but its accuracy is insufficient.